Secret-code apparatus.



PATENTED MAR. 19, 1907.

M. C. HARLAN.

SECRET CODE APPARATUS.

APPLIUATION FILED AUG.14,1903.

of 4wi of letters, numera MARTIN C. HABLAN, 0F STUART, IOWA.

SECRET-CODE APPARATUS.

Specification of Letters Patent.

Patented March 19, 1907.

Application filed August 14, 1903. Serial No. 169.448.

To all whom it may concern;

Be it known that I, MARTIN C. HABLAN, a citizen of the United States, residing at Stuart, in the county of Guthrie and State of Iowa, have invented certain new and useful Im rovements in Secret-Code Apparatus, of which the following is a specification.

The objects of my invention are to provide a device of this class of simple, durable, and inexpensive construction by which a number ersons may communicate or ,correspond tIl each other b means of a combination la, or arbitrary symbols in such a Way that the communication or correspondence will be unintelligible to others except by the use of the secret-code apparatus set to a position previously agreed upon between the parties, and my 'device is especially designed for use in connection with correspondence b letter-writing, telegraph, telephone, or the ike.

A further object is to provide a code apparatus of this class in which the operators may readily and quickly change the code so as tobe unintelligible to others not aware of the change.

My invention consists in certain details 1n the construction, arrangement, and combination of the various parts of the device whereby the objects contemplated are attained, as hereinafter more fully set forth,

pointed out in my claim, and illustrated in the accompanying drawings, in which- Figure 1 shows a to or plan view of the complete apparatus with the movable slide in its closed osition. Fig. 2 shows a like view illustrating the movable slide in an eX- tended osition. Fig. 3 shows'a transverse sectiona view through the indicated line 3 3 of Fig. 1, and Fig.` 4 shows an edge view of one end of the code apparatus.

Referring to the accompanying drawings, the body of the apparatus 1s preferably made of a flat metal strip 10, having its edges bent upwardly and inwardly to overlap the top portion of the body, said overlapping edges having a fiat top surface 11 and their adjacent edges being separated from each other. The mechanical part of the apparatus is completed by means of the flat strip 12, moving ongitudinally between the body-10 and the overlap ing edge portions 1 1, and on one end of the s 'de is a handle 13. lFormedon the upper one of the surfaces 11 I have provided a number of transverse dividing-lines 14, di-4 viding said surface into squares, and in each square a symbol of some kind is placed. Beginning with the left end of the device I have provided in each square a (mnsecutively-a'rranged letter of the alphabet, and following this consecutively-arranged numerals. On the top face of the slide 12 between the edges 11, I ave provided marks 15,(1ivizling the exposed surface of the strip 12 into squares of like size, and in these squares I have placed the letters of the alphabet and numerals arranged exactly the same as those on the said face 11. On the remainin one of the-faces 11 I have provided a series of marks 16, dividing said space into squares of exactly the same size as the other squares, and in said squares I have placed letters, symbols, numerals, &c., arbitrarily arranged. i

In practical usethe operators first simply agree upon the certain position in which the slide 12 is to be placed, and they also agree as to the use of the upper set of symbols or the lower set or an arbitrary arrangement including both. Assumin that it has been previously agreed that t e slide 12 shall be drawn out-until the letter A on the slide is in line with the letter K of the top series, as shown in Fig. 2 of the drawings, and assuming, further, that it is desired to secretly transmit by corres ondence or by the use of the telephone or teegraph the word John, the transmitting operator uses the letters on the slide as his guide, and assuming, further, that it is agreed to use the top series of letters the transmitting operator finds the letter J on the slide and, reading upwardly, finds the letter T 'immediately above the letter J, and the letter T is transmitted. The second letter O on the slide is in line with the letter Y above it, and theletter Y is transmitted. The letter H on the slide is in line with the letter It above it, and the letter R is then transmitted, and th'eletter N on the slide is in line with the letter X on the top row. Hence said letter X is transmitted. The receiving operator finds readily that the letter T is in line with the letter J on the'slide, the letter Y is in line with the letter .O on the slide, the letter t R is in line with the letter H on the slide, and the letter X is in line with the letter N on the slide, so that he may read the secretly-transmitted message upon the slide, while the sending operator may readily read the secret-code message upon the letters at the top. This makes the trans- IOO - this device is susceptible. is very great, be-

cause each time the slide l2 is moved an entirely dill'erent set of symbols or a new combination is formed, and the transmitted message may be further varied by a pre.- vious agreement between the operators that the irst letter shall be read from the top row, and the second from the'bottom row, and so on, or it may be agreed that the first letter shall be read from one space to the right of the top row, the second one space to the left of the to row, the third one space to the right of the ower lrow, and the fourth one space to the left of the lower row, and a number of other combinations may readily be devised.

My invention lis of particular advantage in connection with the use of rural telephones, in which it frequently happens that a large number of subscribers are provided with telephones on party-lines, which party-lines are so arranged that a person at one end of the ltelephone may hear everything transmitted from any one ofthe telephones on the same party-line, and even though each person on a particular party-line should be provided with the same code apparatus such person could, by previous arrangement with the receiving operator, arrange to transmit messages by the use of the secret-mule apparatus with. the slide at a certain predetermined place, as before described, and in this way it would be practically impossible for a on one margin in line with those on the other,

a series of consecutively-arranged letters and numerals on one margin between the lines, a series of alphabetically-arranged symbols on the other margin between the lines, a sheet-metal slide formed with an upturned handle on one end and provided on its central portion with transverse lines spaced apart the same as those on the margins and a series of consecutively-arranged numbers and letters onv the slide between the margins corresponding to the series on one of the margins, for the purposes stated.

MARTIN C. HABLAN. Witnesses:

A; B. JONES, J. P. MCLAUGHLIN. 

